Your System Details List shows that you have a user.js file in the profile folder to initialize some prefs on each start of Firefox.

The user.js file is only present if you or other software has created it, so normally it wouldn't be there.
you can check its content with a plain text editor if you didn't create this file yourself.

The user.js file is read each time you start Firefox and initializes preferences to the value specified in this file, so preferences set via user.js can only be changed temporarily for the current session.

Your System Details List shows that you have a user.js file in the profile folder to initialize some prefs on each start of Firefox.
The user.js file is only present if you or other software has created it, so normally it wouldn't be there.
you can check its content with a plain text editor if you didn't create this file yourself.
The user.js file is read each time you start Firefox and initializes preferences to the value specified in this file, so preferences set via user.js can only be changed temporarily for the current session.
See:
*http://kb.mozillazine.org/Preferences_not_saved
-----
You can use the SearchReset extension to reset some preferences to the default values.
*https://addons.mozilla.org/firefox/addon/searchreset/
Note that the SearchReset extension only runs once and then uninstalls automatically, so it won't show on the "Firefox > Add-ons" page (about:addons).
You can search the <b>about:config</b> page for references to searchgol to be sure that none are left.
Use Reset in the right-click context menu to reset involved prefs.
*http://kb.mozillazine.org/about:config

Question owner

Thanks Neilfox

I found I had to use both Malwarebytes & AdwCleaner to also remove Lyricsfan adverstisements that also popped up. I downloaded AdwCleaner from a cNet web site, which was going to provided additional services I did not require. It is certainly a good lesson to carefully read what you agree to before hitting the 'Next" button.

I have finally regained control back of my computer.

Thanks again for your advice.

Cheers

pgnorman

Thanks Neilfox
I found I had to use both Malwarebytes & AdwCleaner to also remove Lyricsfan adverstisements that also popped up. I downloaded AdwCleaner from a cNet web site, which was going to provided additional services I did not require. It is certainly a good lesson to carefully read what you agree to before hitting the 'Next" button.
I have finally regained control back of my computer.
Thanks again for your advice.
Cheers
pgnorman